Embodiments of the invention relate generally to diagnostic imaging and, more particularly, to an apparatus and method of increasing temporal resolution of an x-ray image.
Typically, in x-ray systems, such as a computed tomography (CT) imaging systems, an x-ray source emits a fan-shaped or cone-shaped beam toward a subject or object, such as a patient or a piece of luggage. Hereinafter, the terms “subject” and “object” shall include anything capable of being imaged. The beam, after being attenuated by the subject, impinges upon an array of radiation detectors. The intensity of the attenuated beam radiation received at the detector array is typically dependent upon the attenuation of the x-ray beam by the subject. Each detector element of the detector array produces an electrical signal indicative of the attenuated beam received by each detector element. The electrical signals are transmitted to a data processing system for analysis, which ultimately produces an image.
Generally, the x-ray source and the detector array are rotated about the gantry within an imaging plane and around the subject. X-ray sources typically include x-ray tubes, which emit the x-ray beam at a focal point. X-ray detectors typically include a collimator for collimating x-ray beams received at the detector, a scintillator for converting x-rays to light energy adjacent the collimator, and photodiodes for receiving the light energy from the adjacent scintillator and producing electrical signals therefrom. Typically, each scintillator of a scintillator array converts x-rays to light energy and discharges the light energy to a photodiode adjacent thereto. Each photodiode detects the light energy and generates a corresponding electrical signal. The outputs of the photodiodes are digitized and then transmitted to the data processing system for image reconstruction.
CT imaging encompasses multiple modalities. For example, one modality includes multi-slice CT imaging, which is often employed for cardiac imaging. Due to the motion of the heart, however, multi-slice CT imaging can suffer from blurring (i.e., poor temporal resolution). One technique that has been employed to minimize blurring includes increasing gantry speed to decrease overall acquisition time. By decreasing CT acquisition time, blurring may be reduced since acquisition occurs over a smaller time period. Generally, however, the weight of a gantry and other forces acting on the gantry limit the speed at which the gantry can operate. Additionally, a reduction in the acquisition time often requires more powerful x-ray tubes to achieve the same image quality.
Another technique to minimize blurring due to motion includes a two-tube-two-detector approach. In such an approach or technique, two tubes operate simultaneously, thus decreasing overall acquisition time. As such, blurring due to motion can be minimized. The cost, however, of two-tube-two-detector CT systems can be prohibitive.
It would therefore be beneficial to design a cost effective system and method that minimizes motion blurring in CT imaging.